Audley Harrison declared recently that he was ready to 'follow in the footsteps of Muhammad Ali, George Foreman, Joe Frazier and Lennox Lewis'. Presumably this is to help them to their feet when they collapse from such a laughable suggestion.

Harrison is a decent boxer. Unbeaten, smart - and going nowhere in a hurry. At 33, he is running out of time and friends. He has just about used up all the goodwill he garnered from the Olympic gold medal he won five years ago. But the irony is he could easily become a world champion, because the standard in boxing's showcase division is at its lowest in living memory. There have been fallow times before, but not quite as all-encompassing as this.

According to a recent and supposedly authoritative poll, the best heavyweight in the world is 35 years old and can't punch. Chris Byrd, who might have made a good limbo dancer, last fought nearly a year ago. It was a split decision, points win over another 35-year-old American, Jameel McCline - and you won't know much about Mr McCline either. In Reno, Nevada, last night Byrd put his IBF title on the line against the spectacularly unknown DaVarryl Williamson.

On the thirtieth anniversary of possibly the best heavyweight fight of all time, it is sobering to reflect on the current crop of heavyweights: anonymous, mediocre, ignored. Muhammad Ali and Joe Frazier did not do each other any favours when they collided that October morning in Manila in 1975; the fight - their third - wrecked them. But they were warriors, committed to providing the sort of contest their slavering constituents craved. There is little contemporary evidence the old game will provide anything so awe-inspiring any time soon.

To illustrate the parlous state of the division, we need only look at the same rating site, boxrec.com, wherein they list the best all-time heavyweights. In the top 50, only two are still active: Mr Bird, and Evander Holyfield. Quite how Bird made it in at number 40 is a mystery - he is regarded as better than, among others, Jack Johnson (46) and Ken Norton (48). This is clearly a nonsense, but the ratings do show how poor the heavyweights are at the moment.

In the current top 10, there are boxers who would not have been good enough to spar with Ali, Louis, Sonny Liston, Rocky Marciano or Larry Holmes, who remains in a seemingly permanent state of semi-retirement, as does the preacher and grilling-machine entrepreneur, George Foreman. Both are over 50 - but that has not stopped them embarrassing themselves in the ring in recent years. They keep coming back because there is nobody to dissuade them, nobody to frighten them into a quiet life of reminiscences.

There are only two British fighters in boxrec.com's current top 50: Matt Skelton at 13 and, at 16, the man he finally meets in December, Danny Williams. Kevin McBride, the Irishman who put the finishing touches to Tyson's career, is considered the fifty-first-best heavyweight in the world and Audley Harrison trails him by seven places - even though the World Boxing Council have him at 14, ahead of McBride and British compatriots Skelton and Williams.

But that's boxing. It is perennially chaotic. Let's look a little closer at the latest top 10. After Byrd comes John Ruiz, Wladimir Klitschko, Hasim Rahman, Vitali Klitschko, James Toney, Luan Krasniqi, Samuel Peter and Calvin Brock. Joe Louis would have beaten them all on the same night.

Ruiz is 33 and counts among his five losses a points decision against the blown-up super-middleweight Roy Jones junior. Wladimir Klitschko was knocked down three times in beating Peter, the over-hyped Nigerian, last weekend.

Rahman is another five-time loser fighting nobodies and who has been manoeuvred into yet another world title fight, this time against Vitali Klitschko. The elder Klitschko is better than any of them but has not fought since beating up Danny Williams in defence of his WBC title last December.

Toney is a fat but talented light-heavyweight chancing his arm with the big boys. Krasniqi is a 34-year-old German who was once knocked out by Przemyslaw Saleta. Peter is either a big, slow Tyson-on-the fade or not even that good (he looked hopeless against Klitschko). And Brock is an unbeaten American being fed boxers such as Kenny Craven, who has lost 15 times. Harrison, realising probably that his credibility has sunk out of sight, has been 'calling out' Brock - along with McCline, Peter and Monte Barrett. These are competitive match-ups, but not exactly the stuff of legend.

Harrison made £1 million in his star-crossed association with the BBC, before the corporation got fed up with ordinary ratings and the fighter's safety-first match-making against washed-up opponents and a collection of small, poor American tourists.

So he decamped to the United States, where his anonymity has grown in a sea of similarly unspectacular performers. As an unbeaten Olympic champion, Harrison ought to have been attracting huge pay cheques and audiences by now - but he has chosen to remain an independent operator and turned away the advances of Don King, the promoter who could make him a star. He might yet come to confront the truth that nearly every heavyweight of the past 30 years has learnt: to make it, you have to go with King.

King's genius is not so much finding great fighters but marketing ordinary fighters as great ones. He could convince the networks that Harrison is special, whereas Harrison can call as many press conferences as he likes and nobody will listen. That's the way the game works. It's a circus and, currently, it is populated by too many clowns.

There are also a worryingly large number of thirtysomethings, most of them in the top flight. Even given that they mature later than lighter boxers, it is as if the division has become a retirement home for fighters willing to carry on pretending they're any good. If people pay to watch them, the fighters will be justified in saying they are filling a need. But it is not much of one.

Since Ali last fought Frazier, the sport has declined alarmingly across the board - in the standard of boxing and in the public's perception of it as mainstream entertainment. The numbers are down - the big guys in America prefer basketball - and so are the revenues. It is a pity because, in among the dross, there have been some wonderful fighters out there in that time.

There are still a lot of terrific boxers around. It's just that not many of them are in the division that historically has carried the rest of the sport. There isn't a go-to champion and, sad as it is to concede, the last excitement machine in the division was Mike Tyson. All he does for the sport now is convince detractors the game is full of maladjusted miscreants.

The man who might once have been considered alongside the great heavyweights of the past was sat on the seat of his pants by McBride this year and then retired - only to turn up on the front pages again accused of yet another fondling misdemeanour while yachting in the Mediterranean. There were stories, not substantiated, that he was going into porn movies. More than likely, it was Tyson's twisted sense of humour at work. Lately he has been in Chechnya opening a boxing gym and asking everyone to stop killing each other.

Tyson was in some of boxing's most memorable scraps before he descended into a hell of his own making. But he also reigned when there was hardly a heavyweight worth sharing ring-space with him. Only Holyfield and Lennox Lewis were in his class - and they trounced him.

It is easy enough to remember the great heavyweight clashes since 1975 because there have been fewer of them in that time than in the decades before.

Riddick Bowe's memorable first collision with Holyfield bears comparison with many of Ali's fights. So does Holyfield's dismantling of Tyson. And when Tyson took Michael Spinks apart in a minute-and-a-half, we imagined we were in the presence of a boxing immortal. How wrong we were.

It is indisputable that the best of boxing resides way in the past. You do not have to be a purblind romantic to acknowledge that. In 2002, Ring magazine produced its list of the best 80 fighters in the previous 80 years. Only 14 boxed after 1975.

The theory in boxing, as in sport generally, is that these cycles change, that at some point another world-beater will arrive to ignite the business. That may well be so, but a detailed trawl of what's on offer suggests it won't be happening in the immediate future.

Using Harrison's Olympic victory as a starting point, nobody in the past five years, apart from Lennox Lewis (who was a genuine champion of the highest class), deserves to be ranked alongside those heavyweights we stayed up all night to see.

In the Sydney semi-final, Harrison boxed perfectly to beat the Italian Paulo Vidoz. It looked as if the Londoner would live up to his many boasts when he turned professional, yet he has still to fight for even a local title. Last night Vidoz fought Michael Sprott from Reading for the vacant European championship in Germany.

Also on the bill in Oldenberg was a fighter who knocked out Vidoz last year, the unbeaten 7ft Russian Nikolay Valuev, entertainingly billed as The Beast From The East. This is probably the best nom de guerre since Primo Carnera carried around with him the mildly mocking moniker of The Ambling Alp.

Valuev's opponent last night was the American journeyman Larry Donald, who, without embarrassment, glories in the ring name The Legend, and their contest was announced as being an eliminator for the World Boxing Association title. Donald was knocked out three years ago by Vitali Klitschko and, at 38, his best days are long gone. It is difficult to imagine flirting more outrageously with farce.

It is not that these fighters don't deserve their day in the sun. It's a bit much, though, to expect anyone to believe they are legitimate contenders. When Ali fought Frazier, we were left in no such doubt - and they were heading for their own sunsets.

If Audley Harrison really wants to leave even a small mark on boxing's history, he has the cleanest canvas imaginable on which to work.

Noble art or a name game?

If there is a better name in sport than 'Piano Mover' Jones, I haven't heard it. Long before wrestling cottoned on to the notion, boxing provided us with a galaxy of wonderful ways to dress up often ordinary fighters. Piano Mover (sometimes known as Honeyboy) was an early opponent for Archie Moore - who gloried in the nickname 'Ol' Mongoose'. Moore, a great eccentric as well as a great boxer, claimed he had several amateur fights as 'The Fourth Of July Kid'. He worked when names were invented on a whim to disguise the identity of the owner or simply to sell tickets. Moore fought guys named 'Ham Pounder', 'Sammy Slaughter', 'Big Boy Hogue', 'Cocoa Kid', and 'the Alabama Kid'. There were also regular Kids, Fightings, Tigers, Sonnys and Battlings, not to mention Irish this and Irish that.

In our time, Chuck Wepner probably owns the most evocative name - the 'Bayonne Bleeder'. Some names betray too much of the fighter's ego - Oscar 'Golden Boy' De La Hoya, for example. Marvin Hagler changed his name by deed poll to 'Marvelous', then lost to 'Sugar Ray Leonard'. Sugar Ray, of course, borrowed the sugar from 'Sugar Ray Robinson' (real name Walker Smith) - who borrowed it himself from an inferior contemporary.

Some nicknames tempt fate. Robin Reid once called himself the 'Grim Reaper', not the best of taste in a sport where death lurks. Ditto, Bernard 'The Executioner' Hopkins. Lew Jenkins called himself 'Living Death'. Eric Esch is not a proper fighter, more a showman with a whack, but he did invent a memorable name for himself: 'Butterbean'. Not because he looked like one but because he used to eat them.

The most absurd nickname belongs to a fictional fighter, Apollo 'The Count of Monte Fisto' Creed - which was marginally ahead of his opponent's, Rocky 'The Italian Stallion' Balboa. I never discovered where Andrew 'Six Heads' Lewis got his inspiration from. And James 'Lights Out' Toney has a surreal ring about it. What were they on?